Nine people reportedly came down with a stomach illness after taking part in the event at the Newham Drain at Antons Gowt earlier this month.
The Environment Agency (EA) and the Health Security Agency (HSA) both launched investigations into the matter, amid reports of pollution entering the watercourse.
The EA says it is not yet in a position to provide an update, but the HSA says it has concluded its investigation, saying ‘available sampling indicated norovirus’.
Norovirus – also known as the winter vomiting bug – is a stomach bug that causes vomiting and diarrhoea.
It is spread through close contact with someone with norovirus, touching contaminated surfaces or objects, then touching the mouth, or eating food prepared or handled by someone with norovirus.
An HSA spokesman added: “We cannot say for certain that someone was carrying the virus prior to the event but this is the most likely explanation.”
The raft race was organised by Katie Chalmers – a councillor at Boston Borough Council – although was not a council event.
Speaking to The Standard for the following week’s paper, Coun Chalmers said: “The race started a mile away where the water was clear, and it wasn’t until we got to the end near the little bridge that we started to smell that something wasn’t right.”
She said she walked up the bank of the drain to try and locate the source of the smell.
“It was revolting,” she said. “At that point we told everyone to get out of the water.”
Read the original piece here.